This sounds strange but my husband and I swear by pickle juice and yellow mustard. I also notice I get more hand, finger, and arm cramps when dehydrated. Now, it could also be our cervical spine issues and surgeries haven't fully resolved that area. But, try the pickle juice and/or mustard. I also use CBD roll-on oils on those areas if you want to stay on the natural path. I've used Voltaren also. Hope it helps. Take care!